Eid ul-Fitr, the Muslim holiday marking the end of the fasting month of Ramadan, is supposed to be a joyous occasion. But in the U.S.-allied Persian Gulf nation of Bahrain, where the Sunni-dominated government has arrested scores of Shi’ite opposition activists in recent weeks, many celebrated in fear.

The current crackdown comes in advance of next month’s parliamentary elections and follows weeks of rioting and occasional property destruction by the majority Shi’ites, who have long demanded a greater share of the island kingdom’s resources and more say in its political process.

While the streets have largely quieted in response to the arrests, an explosion apparently targeting the country’s security services was reported Tuesday south of the capital of Manama. No one was injured in the blast.

Confirmed detainees include 23 prominent Shi’ite political activists, charged with plotting the government’s overthrow, as well as the proprietor of the country’s most popular website, charged with “spreading false information.” But sources on the ground told The Washington Times that the recent arrests have been more far-reaching.

“We stopped counting at 250,” said Nabeel Rajab, president of the Bahrain Center for Human Rights. “People are being arrested on an hourly basis.” Other activists peg the number somewhat lower but acknowledge that continued detentions and periodic releases make an exact number elusive.

“It’s been coming to this for quite a long time,” said Toby Jones, a Rutgers University professor of Middle East History who lived in Bahrain from 2003 to 2006 while working for the International Crisis Group. “Since the summer of 2005, we’ve seen an escalation in [street violence from the Shia]. Over time, it’s grown increasingly provocative and confrontational, and the state has simultaneously become more heavy-handed and brutal.”

The State Department declined to comment for this report. But some say the prolonged incommunicado detentions and widespread allegations of severe torture invariably force the Obama administration into choosing between American ideals and interests.

“Bahrain is a critical country to us,” said Ronald E. Neumann, former U.S. ambassador to Bahrain. “It provides the basing for our 5th fleet. It has provided us with refueling support for both the wars in Iraq and Afghanistan. It’s not a place where you want to just tear up your relationship.”

The situation is complicated by heightening U.S. tensions with Iran, whose growing regional influence frightens neighboring Arab states — particularly those, like Bahrain, with large Shi’ite populations.

“American policy operates under the presumption that Iran has a deep reach into Iraq, it has a deep reach into Saudi Arabia, and that it’s able to shape the minds of Bahraini Shias as well,” Mr. Jones said.

“So to then criticize the Bahrainis for using precisely that excuse to crack down on the Shia is inconsistent with America’s broader geostrategic position. If America calls all these people democrats and says they’re just advocating for greater political participation or whatever, then it undermines Bahrain’s claim that we’re dealing with a potential fifth column here.”

The highest-profile string of arrests involves Abduljalil al-Singace, a leader in the Shi’ite political movement Haq, and 22 other prominent activists, who stand accused of belonging to a “terror network” seeking the government’s overthrow — a charge that carries the death penalty.

With no trial date set thus far, however, concern has focused on how Mr. al-Singace and others are being treated in detention.

“What we’ve heard about his condition is very bad,” said Mr. al-Singace’s daughter Zahra, who has had no direct contact with her father since she saw him arrested at the airport on Aug. 13 upon his return from London, where he had criticized Bahrain’s human rights practices before the House of Lords.

“He has been beaten to the point that he has almost lost his ability to hear,” Ms. Al-Singace said. “They took his glasses and crutches, which he can’t walk without, and blinded his eyes for more than two weeks. They also used electricity shocks on his nipples and ears.”

“None of our clients has been given the chance to contact their relatives or to meet them,” Mohammed Ahmad, one of the attorneys for Mr. al-Singace and the other defendants, told the Times. “These people have been totally denied every single right given to them under the constitution.”

Jenan Al Oraibi, whose husband, Ali Abdulemam — founder of Bahrain Online, the country’s wildly popular web forum — was arrested last Saturday and charged with “spreading false information,” has taken refuge at her father’s house with her 4-year-son and 8-month-old twin daughters.

“Every time my son sees me crying, he will ask me, ‘Why are you crying? What happened? Where’s my father?’” Ms. Oraibi told The Times. “All I can say to him is that ‘your father is traveling and he will be back soon.’ Sometimes, I see him quiet, and I know that he wishes to go back to our flat, to stay in his room, to play with his toys. It’s a very difficult situation.”

Mr. Abdulemam has been arrested before, in 2005, but Ms. Oraibi said that experience was completely different.

“He gave us a call, they allowed us to see him, we were sure they weren’t going to torture him,” she said. “And now it’s a totally different thing. I don’t know anything about Ali other than what I read in the newspapers — and I don’t know if I can trust any of it because it’s coming from the government.”

The Bahraini Embassy did not respond to repeated calls seeking comment. But Jamal Fakhro, first deputy chairman of the government-appointed Shura Council, Bahrain’s upper legislative body, claimed that authorities are allowing doctors to investigate torture allegations and expressed confidence that all laws were being followed.

Human rights activists from multiple organizations, however, told The Times that the detentions — and the alleged maltreatement of the detainees — are only part of the story.

“We’ve also documented a number of instances of what we call ‘kidnappings,’” said Maryam al-Khawaja of the Bahrain Center for Human Rights. “These are cases where security forces go take someone from the street, blindfold them, take them somewhere unknown, take pictures of them naked which they threaten them with, threaten them with sexual assault, sometimes actually sexually assault them, beat them up severely, and then haul them back on the street half-naked.”

“Human rights activists have to live in continuous fear because we know we’re being targeted by the government,” said Ms. al-Khawaja, who fled to London in recent weeks. “You’d find that the activists are awake until 3:15 or 3:30 in the morning because they’re just sitting there waiting to see whether it’s the night that they’re going to get arrested.

“When I was in Bahrain,” she added, “I would always make sure to lock the door when I got into the car so just in case they came to get me, I would have time to make one last phone call.”

Last week, Abdullah al-Derazi, president of the Bahrain Human Rights Society — which, unlike the Bahrain Center for Human Rights, enjoys government sanction — was fired and replaced by a government-friendly administrator. He told The Times that his group, whose board was also dissolved, is suing the government.

Joe Stork, deputy director of Human Rights Watch’s Middle East and North Africa division, decried the government campaign against Mr. Rajab, Mr. al-Derazi, and other human rights activists. Noting that his organization released a report earlier this year on torture by Bahrain’s security services, he said that “unfortunately, we find the [torture] allegations all too credible.”

For Mr. Stork, whose division covers 17 countries over an area spanning from Morocco to Iran, there is a tragic irony to the current situation. He said that after the 1999 ascension of the current king, Hamad ibn Isa Al Khalifah, “Bahrain was a leader in the region in undertaking serious, substantive reforms on human rights.”

“When we released our report in February in Manama,” he recalled, “one of the first things I said at the press conference was, ‘I want to be clear: We’re not saying it’s the bad old days in Bahrain. There’s a world of difference.’ I think if I were having a public meeting in Bahrain today, I’d have to say it’s getting pretty close to the bad old days.”